求助
指针：int a=5;
int* p=0;
p=&a;
你们谁能帮我举个指针函数，函数指针的例子。
其定义格式如下所示：
返回类型标识符 *返回名称（形式参数表){ 函数体; }
for example:
#include<iostream>
using namespace std;
float *find(float(*pionter)[4],int n)//定义指针函数
{
float *pt;
pt=*(pionter+n);
return pt;
}
int main()
{
static float score[][4]={{60,70,80,90},{56,89,34,45},{34,23,56,45}};
float *p;
int i,m;
cout<<"Enter the number to be found:";
cin>>m;
cout<<"the score of NO.%d are:\n";
p=find(score,m);
for (i=0;i<4;i++)
printf("%5.2f\t",*(p+i));
return 0;
}
using namespace std;
float *find(float(*pionter)[4],int n)//定义指针函数
{
float *pt;
pt=*(pionter+n);
return pt;
}
int main()
{
static float score[][4]={{60,70,80,90},{56,89,34,45},{34,23,56,45}};
float *p;
int i,m;
cout<<"Enter the number to be found:";
cin>>m;
cout<<"the score of NO.%d are:\n";
p=find(score,m);
for (i=0;i<4;i++)
printf("%5.2f\t",*(p+i));
return 0;
}
函数指针是指向函数的指针变量。
“函数指针”本身首先应是指针变量，只不过该指针变量指向函数。这正如用指针变量可指向整型变量、字符型、数组一样，这里是指向函数.
#include<iostream>
using namespace std;
void func1();
void func2();
int main(void)
{
void(*funcp)(); //declare a pointer to a function
//put an address in the pointer,and call the function through the pointer
funcp = func1;
(*funcp)();
funcp = func2;
(*funcp)();
return 0;
}
void func1()
{
cout<<"Func1"<<endl;
}
void func2()
{
cout<<"Func2"<<endl;
}
using namespace std;
void func1();
void func2();
int main(void)
{
void(*funcp)(); //declare a pointer to a function
//put an address in the pointer,and call the function through the pointer
funcp = func1;
(*funcp)();
funcp = func2;
(*funcp)();
return 0;
}
void func1()
{
cout<<"Func1"<<endl;
}
void func2()
{
cout<<"Func2"<<endl;
}
